I need a new pair of tyres on my rear and will be getting the MPSS again - partly because it will match the fronts, and partly because they are stunning. I find my MPSS tyres great in dry and the wet. But cold and wet is where it's a slightly different ball game. Don't get me wrong, they're not ditchfinders, but you have to be careful on a 5c damp winters day as you do in any car really.
I'm not completely sold on the CSC6. I'm sure they are great tyres in the grip/feel category, but they've received quite a lot of anecdotal online criticism for the bad wear rates.